Rainbow trout (Oncorhynchus mykiss, Walbaum 1792) adenocarcinoma investigation with various diagnostic imaging techniques.

Diagnostic imaging techniques provide a new aspect of the ante-mortem and post-mortem diagnostics in fish medicine. Ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI) can provide more information about the internal organs and pathognomic lesions. The authors used diagnostic imaging techniques to evaluate and describe the neoplastic malformation in a 3-year-old female rainbow trout (Oncorhynchus mykiss). The fish was examined with Siemens Somatom Definition AS + CT scanner and Siemens Biograph mMR scanner. The animal was lethargic and showed anorectic signs and muscular dystrophy. During the post-mortem investigation, histopathology and immunohistochemistry were also performed allowing us to identify the neoplasms. The results showed a large soft tissue mass in the first mid-intestine segment, which proved to be an adenocarcinoma. This subsequently led to digestion problems and absorption disorders. Immunohistochemically, neoplastic cells of carcinoma revealed E-cadherin and pancytokeratin positivity. This is the first study to report the use of MRI and CT for studying gastrointestinal adenocarcinoma in rainbow trout.

Structural similarity of human papillomavirus E4 and polyomaviral VP4 exhibited by genomic analysis of the common kestrel (Falco tinnunculus) polyomavirus.

Polyomaviruses are widely distributed viruses of birds that may induce developmental deformities and internal organ disorders primarily in nestlings. In this study, polyomavirus sequence was detected in kidney and liver samples of a common kestrel (Falco tinnunculus) that succumbed at a rescue station in Hungary. The amplified 5025 nucleotide (nt) long genome contained the early (large and small T antigen, LTA and STA) and late (viral proteins, VP1, VP2, VP3) open reading frames (ORFs) typical for polyomaviruses. One of the additional putative ORFs (named VP4) showed identical localization with the VP4 and ORF-X of gammapolyomaviruses, but putative splicing sites could not be found in its sequence. Interestingly, the predicted 123 amino acid (aa) long protein sequence showed the highest similarity with human papillomavirus E4 early proteins in respect of the aa distribution and motif arrangement implying similar functions. The LTA of the kestrel polyomavirus shared <59.2% nt and aa pairwise identity with the LTA sequence of other polyomaviruses and formed a separated branch in the phylogenetic tree among gammapolyomaviruses. Accordingly, the kestrel polyomavirus may be the first member of a novel species within the Gammapolyomavirus genus, tentatively named Gammapolyomavirus faltin.

MANDIBULAR FRACTURES IN GIRAFFES (GIRAFFA CAMELOPARDALIS) IN EUROPEAN ZOOS.

Following a case of mandibular fracture in a giraffe (Giraffa camelopardalis) at the Budapest Zoo, a survey was conducted across European zoological institutions with the support of the European Association of Zoos and Aquariums Giraffe Ex situ Programme (EAZA Giraffe EEP) to help identify the incidence, potential causes, and management of such injuries. Two hundred sixteen zoos keeping giraffes were invited to participate in the survey. Eighty-six responses were received, 14 of which (16.3%) reported jaw fractures with various causes in their giraffes. Of these responses, hay racks, where the muzzle of the giraffe could fit between the grid of feeding contraptions, were associated with mandibular fractures in seven cases (50.0%). Most giraffes were managed surgically (10/14; 71.4%), two were managed medically (14.3%), one was euthanized because of the severity of the injury (7.1%), and one was only diagnosed with a mandibular fracture postmortem. One giraffe died owing to postanesthetic complications; all other individuals had a full recovery. Most mandible fractures occurred in relatively young giraffes (between 5 wk and 8 yr with an average of 3.4 yr). Based on these findings, facilities with giraffe should evaluate their hay feeders for mandible entrapment risk, especially if they house young individuals.

A novel gammapolyomavirus in a great cormorant (Phalacrocorax carbo).

In this study, the complete genome of a novel polyomavirus detected in a great cormorant (Phalacrocorax carbo) was characterized. The 5133-bp-long genome of the cormorant polyomavirus has a genomic structure typical of members of the genus Gammapolyomavirus, family Polyomaviridae, containing open reading frames encoding the large and small tumor antigens, viral proteins 1, 2, and 3, and the X protein. The large tumor antigen of the cormorant polyomavirus shares 45.6-50.4% amino acid sequence identity with the homologous sequences of other gammapolyomaviruses. These data, together with results of phylogenetic analysis, suggest that this cormorant polyomavirus should be considered the first member of a new species within the genus Gammapolyomavirus, for which we propose the name "Phalacrocorax carbo polyomavirus 1".

Novel Circoviruses from Birds Share Common Evolutionary Roots with Fish Origin Circoviruses.

Circoviruses occur in a variety of animal species and are common pathogens of mammalian and avian hosts. In our study internal organ samples of wild birds were processed for screening of circoviral sequences. Two novel viruses were identified and characterized in specimens of a little bittern and a European bee-eater that suffered from wing injuries, were weakened, had liver or kidney failures, and finally succumbed at a rescue station. The 1935 nt and 1960 nt long viral DNA genomes exhibited a genomic structure typical for circoviruses and were predicted to encode replication-associated protein in the viral strand, and a capsid protein in the complementary strand of the replicative intermediate DNA form. The genome of the newly described viruses showed 37.6% pairwise identity with each other and ≤41.5% identity with circovirus sequences, and shared a common branch with fish, human and Weddel seal circoviruses in the phylogenetic tree, implying evolutionary relationship among the ancestors of these viruses. Based on the results the little bittern and European bee-eater circoviruses represent two distinct species of the Circovirus genus, Circoviridae family.

Intussusception caused by intestinal neoplasia in mature rainbow trout (Oncorhynchus mykiss, Walbaum 1792).

The aquaculture industry is growing and includes the farming and breeding of more than 580 aquatic species worldwide. The rainbow trout (Oncorhynchus mykiss, Walbaum 1792) is the most commonly bred trout species in Hungary. As broodfish form the basis of most fish farms, investigation into tumours occurring in trout, although under-researched, has proven to be a valuable and necessary field of study. During our investigation, we examined a broodstock of 3- to 6-year-old rainbow trouts (800) affected with idiopathic intestinal tumours (3%) which had consequentially led to ileus (40%). While performing necropsy, initial pathological observations showed intussusceptions. Tumours were discovered upon opening the body cavity, as well as metastasis forming in the livers and in the vessels of the gills. Histopathological and immunohistochemical tests allowed us to identify the neoplasms. The primary adenocarcinoma was found to have been developed within the intestines of the fish. The tumour tissue broke through the basal membrane and infiltrated the propria, protruding asymmetrically into the lumen of the mid-intestines, causing it to narrow significantly. This subsequently led to passage disorders, invagination of the intestinal segment and finally the emaciation of the fish. Histopathological and immunohistochemical inspection of the tumour cells displayed a high mitotic index, confirming malignancy.